<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			div {
				/* height: 100px; */
				color: white;
				text-align: center;
				line-height: 100px;
				/* float: left;
				height: 300px;
				width: 150px; */
				float: right;
				width: 150px;
				height: 300px;
			}

			#box1 {
				background-color: red;
				/* float: right; */
			}

			#box2 {
				background-color: blue;
			}

			#box3 {
				background-color: green;
				float: left;
			}
		</style>
	</head>
	<body>
		<div id="box1">第1栏(1)</div>
		<div id="box2">第2栏(2)</div>
		<div id="box3">第3栏(3)</div>
	</body>
</html>
